Various kinds of electronic information products, such as computers, are now widely adopted and applied in different commercial and industrial fields. To meet consumers' demands, electronic information products have been designed to have high operating speed and increased access capacity. However, components in the electronic information products would produce a high amount of heat when they operate at high speed.
For example, among others; the central processing unit (CPU) of a computer produces the largest part of heat in the computer. When the heat produced by the CPU gradually increases, the computer would have reduced performance. And, when the produced heat has accumulated in the computer to exceed an allowable limit, the computer is subject to the danger of shutdown or even becoming seriously damaged. Moreover, to solve the problem of electromagnetic radiation, a case is usually used to enclose all the important computer components and elements therein. Therefore, it is a very important matter to quickly dissipate the heat produced by the CPU and other heat-producing elements in the computer case.
A common way to dissipate the heat produced by the CPU is to mount a heat sink and a cooling fan atop the CPU. The heat sink has a first side formed with a plurality of radiating fins. An opposite second side of the heat sink without the radiating fins is in direct contact with the CPU, so that heat produced by the CPU is absorbed by the heat sink at the second side contacting with the CPU and then transferred to the radiating fins at the first side and finally radiated from the radiating fins into ambient air. And, the cooling fan produces airflows to carry away hot air around the CPU and the heat sink, so as to achieve the purpose of quick heat dissipation.
FIG. 1 is a sectional view of a conventional cooling fan 1, which includes a base 11, a motor 12, and a blade hub 13. The base 11 mainly has a bearing cup 111 formed thereon for receiving a bearing 112 therein. A rotary shaft 113 is extended through the bearing 112, and the motor 12 is externally fitted around the bearing cup 111 in a tight fit relation. The blade hub 13 is then mounted atop the motor 12 and the bearing 112. The rotary shaft 113 has an end pivotally turnably fitted in a rear center of the blade hub 13, so that the blade hub 13 is rotatably connected to the bearing via the rotary shaft 113. When the motor 12 is assembled to the bearing cup 111, the motor 12 is in an interference fit relation with the bearing 112. Before the motor 12 is interference-fitted to the bearing 112, there is a glue dispensing procedure to apply a catalyst and glue on an outer wall surface of the bearing 112. Thereafter, a motor compressing procedure is performed to force the motor 12 onto an outer side of the bearing 112, so that the motor 12 is connected to the bearing cup 111 by way of interference fit. With the motor 12 connected to the bearing cup 111 by way of interference fit, the bearing cup 111 tends to compress against the bearing 112 received therein and causes deformation of the bearing 112 as well as noise during the operation of the cooling fan.
In brief, the conventional cooling fan, due to its assembling structure, has the following disadvantages: (1) requiring an additional glue dispensing procedure; (2) requiring to tight fit the motor around the bearing cup; (3) tending to cause deformation of the bearing; and (4) tending to cause noise during the operation of the cooling fan.
It is therefore tried by the inventor to develop a cooling fan with quick assembling structure to overcome the problems in the conventional cooling fan.